".....But like many others, he speculated that the diners might have come down with “winter vomiting disease,” a highly contagious type of norovirus, or Norwalk-like virus, that has been cutting a swath through Britain. It has been particularly virulent in schools and hospitals.

Dr. Steve Field, chairman of the Royal College of General Practitioners, said that the reported symptoms seemed more in line with the vomiting illness than with, say, food poisoning. If just one person in the restaurant had it, he said, it could have been passed quickly to everyone else.

Mr. Bicknell said that “funnily enough, I had this sickness and diarrhea last weekend, and the last time I ate at the Fat Duck was about five years ago....”